compare symbol names with `equal'

[bpt/emacs.git] / lisp / desktop.el

diff --git a/lisp/desktop.el b/lisp/desktop.el
index dbddfb7..26d288b 100644 (file)
--- a/lisp/desktop.el
+++ b/lisp/desktop.el
@@ -174,8 +174,8 @@ For further details, see info node `(emacs)Saving Emacs Sessions'."
   :global t
   :group 'desktop
   (if desktop-save-mode
-      (desktop-auto-save-set-timer)
-    (desktop-auto-save-cancel-timer)))
+      (desktop-auto-save-enable)
+    (desktop-auto-save-disable)))
 
 (defun desktop-save-mode-off ()
   "Disable `desktop-save-mode'.  Provided for use in hooks."
@@ -207,13 +207,17 @@ determine where the desktop is saved."
 
 (defcustom desktop-auto-save-timeout auto-save-timeout
   "Number of seconds idle time before auto-save of the desktop.
+The idle timer activates auto-saving only when window configuration changes.
 This applies to an existing desktop file when `desktop-save-mode' is enabled.
 Zero or nil means disable auto-saving due to idleness."
   :type '(choice (const :tag "Off" nil)
                  (integer :tag "Seconds"))
   :set (lambda (symbol value)
          (set-default symbol value)
-         (ignore-errors (desktop-auto-save-set-timer)))
+         (ignore-errors
+          (if (and (integerp value) (> value 0))
+              (desktop-auto-save-enable value)
+            (desktop-auto-save-disable))))
   :group 'desktop
   :version "24.4")
 
@@ -387,15 +391,18 @@ modes are restored automatically; they should not be listed here."
   :group 'desktop)
 
 (defcustom desktop-restore-frames t
-  "When non-nil, save frames to desktop file."
+  "When non-nil, save and restore the frame and window configuration.
+See related options `desktop-restore-reuses-frames',
+`desktop-restore-in-current-display', and `desktop-restore-forces-onscreen'."
   :type 'boolean
   :group 'desktop
   :version "24.4")
 
 (defcustom desktop-restore-in-current-display nil
-  "If t, frames are restored in the current display.
-If nil, frames are restored, if possible, in their original displays.
-If `delete', frames on other displays are deleted instead of restored."
+  "Controls how restoring of frames treats displays.
+If t, restores frames into the current display.
+If nil, restores frames into their original displays (if possible).
+If `delete', deletes frames on other displays instead of restoring them."
   :type '(choice (const :tag "Restore in current display" t)
                 (const :tag "Restore in original display" nil)
                 (const :tag "Delete frames in other displays" delete))
@@ -403,11 +410,13 @@ If `delete', frames on other displays are deleted instead of restored."
   :version "24.4")
 
 (defcustom desktop-restore-forces-onscreen t
-  "If t, offscreen frames are restored onscreen instead.
-If `all', frames that are partially offscreen are also forced onscreen.
-NOTE: Checking of frame boundaries is only approximate and can fail
-to reliably detect frames whose onscreen/offscreen state depends on a
-few pixels, especially near the right / bottom borders of the screen."
+  "If t, restores frames that are fully offscreen onscreen instead.
+If `all', also restores frames that are partially offscreen onscreen.
+
+Note that checking of frame boundaries is only approximate.
+It can fail to reliably detect frames whose onscreen/offscreen state
+depends on a few pixels, especially near the right / bottom borders
+of the screen."
   :type '(choice (const :tag "Only fully offscreen frames" t)
                 (const :tag "Also partially offscreen frames" all)
                 (const :tag "Do not force frames onscreen" nil))
@@ -416,8 +425,8 @@ few pixels, especially near the right / bottom borders of the screen."
 
 (defcustom desktop-restore-reuses-frames t
   "If t, restoring frames reuses existing frames.
-If nil, existing frames are deleted.
-If `keep', existing frames are kept and not reused."
+If nil, deletes existing frames.
+If `keep', keeps existing frames and does not reuse them."
   :type '(choice (const :tag "Reuse existing frames" t)
                 (const :tag "Delete existing frames" nil)
                 (const :tag "Keep existing frames" :keep))
@@ -839,12 +848,13 @@ QUOTE may be `may' (value may be quoted),
   "Convert VALUE to a string that when read evaluates to the same value.
 Not all types of values are supported."
   (let* ((print-escape-newlines t)
+        (print-length nil)
+        (print-level nil)
         (float-output-format nil)
         (quote.sexp (desktop--v2s value))
         (quote (car quote.sexp))
-        (txt
-          (let ((print-quoted t))
-            (prin1-to-string (cdr quote.sexp)))))
+        (print-quoted t)
+        (txt (prin1-to-string (cdr quote.sexp))))
     (if (eq quote 'must)
        (concat "'" txt)
       txt)))
@@ -1118,6 +1128,10 @@ Using it may cause conflicts.  Use it anyway? " owner)))))
                (unless desktop-dirname
                  (message "Desktop file in use; not loaded.")))
            (desktop-lazy-abort)
+           ;; Temporarily disable the autosave that will leave it
+           ;; disabled when loading the desktop fails with errors,
+           ;; thus not overwriting the desktop with broken contents.
+           (desktop-auto-save-disable)
            ;; Evaluate desktop buffer and remember when it was modified.
            (load (desktop-full-file-name) t t t)
            (setq desktop-file-modtime (nth 5 (file-attributes (desktop-full-file-name))))
@@ -1170,6 +1184,7 @@ Using it may cause conflicts.  Use it anyway? " owner)))))
                                  (set-window-prev-buffers window nil)
                                  (set-window-next-buffers window nil))))
            (setq desktop-saved-frameset nil)
+           (desktop-auto-save-enable)
            t))
       ;; No desktop file found.
       (desktop-clear)
@@ -1216,6 +1231,15 @@ directory DIRNAME."
 ;; Auto-Saving.
 (defvar desktop-auto-save-timer nil)
 
+(defun desktop-auto-save-enable (&optional timeout)
+  (when (and (integerp (or timeout desktop-auto-save-timeout))
+            (> (or timeout desktop-auto-save-timeout) 0))
+    (add-hook 'window-configuration-change-hook 'desktop-auto-save-set-timer)))
+
+(defun desktop-auto-save-disable ()
+  (remove-hook 'window-configuration-change-hook 'desktop-auto-save-set-timer)
+  (desktop-auto-save-cancel-timer))
+
 (defun desktop-auto-save ()
   "Save the desktop periodically.
 Called by the timer created in `desktop-auto-save-set-timer'."
@@ -1238,7 +1262,7 @@ after that many seconds of idle time."
   (when (and (integerp desktop-auto-save-timeout)
             (> desktop-auto-save-timeout 0))
     (setq desktop-auto-save-timer
-         (run-with-idle-timer desktop-auto-save-timeout t
+         (run-with-idle-timer desktop-auto-save-timeout nil
                               'desktop-auto-save))))
 
 (defun desktop-auto-save-cancel-timer ()